Harald Ringstorff (born 25 September 1939 in Wittenburg, Mecklenburg) is a German politician of the Social Democratic Party (SPD) and was the 3rd Minister President of the state of Mecklenburg-Vorpommern. He headed a coalition government of the SPD and PDS (since 2007 the Left Party, Die Linke) from 1998 until 2006, and subsequently headed a coalition between the SPD and CDU. He was the 61st President of the Bundesrat in 2006/07.
After his Abitur and military service, Ringstorff studied Chemistry at the University of Rostock. He received his Ph.D. in 1969. Afterwards he worked as a chemist for the Rostock dockyards. From 1987 to 1990 he was director of the branch office of the VEB Kali-Chemie ("people's enterprise for potash chemistry").
In 1989 Ringstorff was a founding member of the Social Democratic Party in the GDR and a member of the freely elected Volkskammer of 1990. From 1990 to 2003 he was chairman of the SPD in Mecklenburg-Vorpommern.
Since 1990 Ringstorff has been a member of the Landtag of Mecklenburg-Vorpommern where he served as parliamentary leader of the SPD from 1990–1994 and 1996-1998. In between he was Minister for Economic and European Affairs and vice-minister-president in a coalition government with the CDU under minister-president Berndt Seite (CDU).
In 1998, the SPD agreed to form a coalition with the PDS (now Left Party), a move controversial within the party. Ringstorff was elected minister-president. His coalition government was re-elected in 2002. After the elections of 2006, he decided to switch to a coalition with the CDU, which would have a more comfortable majority in parliament.
On 6 August 2008 Ringstorff let it be known that he wished to resign as minister-president because of his age. On 6 October he was succeeded in the office by Erwin Sellering.